Hi there.
Avastin is a targeted therapy. It cuts off the blood supply to the tumor. Tumors need a good supply of blood to grown. While the Avastin is cutting off the blood supply, the CPT-11 (Irinotecan) kills the cancer cells. Anyhow, this is what these two infusions are supposed to do. My husband has been on this treatment regimen since July 25, 2007. He was put on this after radiation and Temodar failed to work. Not only did the tumor not shrink -the post radiation MRI showed progression. So, if your mom's tumor is stable, that is a good thing.
The Avastin and CPT-11 have not caused noticable neurological deficits in my husband. He does have some slight confusion but I think its more likely the tumor - but maybe not. There is a lot of talk out there about "chemo brain."
He is being treated at Duke. I'd let them work with your Mom's doctors! We're at 13 month from diagnosis and still doing well.
Best to you!
Barb